The present invention relates to a process for the preparation of monoacyl polyalkylene polyamines. The monoacyl polyalkylene polyamines which can be prepared by the present process may be represented by the formula ##STR1## wherein R is straight or branched chain alkyl of from 7 to 21 carbon atoms or mixtures thereof, n is an integer of from 1 to 3 and X is straight or branched chain alkylene or hydroxyalkylene of from 2 to 6 carbon atoms.
The prior art shows many processes for combining amines and fatty acids or esters. Reactions that are satisfactory when amines are involved are often unsatisfactory when diamines are combined with a fatty acid or ester. When diamines are involved, the processes are more complex and more difficult to control as a result of the formation of various side products. See, for example, U.S. Pat. No. 1,947,951, 2,387,201 and 2,750,366. In an article entitled "The Aminolysis of Esters. A Preliminary Study", J. Am. Chem. Soc., 72:4149 (1950), Baltzly et al., reported the results of aminolysis of esters utilizing monoamines in the presence of solvents including alcoholic solvents. Monoacyl polyalkylene polyamines can be prepared by reacting a suitable fatty acid or ester with a diamine at elevated temperatures, e.g., 100.degree.-250.degree. C. for a period of several hours. This reaction can be shown schematically when ethylenediamine is utilized as follows: ##STR2## Although this process results in the preparation of some of the desired end-product, there is significant contamination of the end-product with undesirable diamide by-products which must be separated out. There may also be off-color and malodor problems as a result of the high temperatures required. Furthermore, due to the temperatures required, the process is energy inefficient and expensive.
It is, therefore, an object of this invention to provide a novel process for the preparation of monoacyl polyalkylene polyamines.
It is a further object of this invention to provide a process for the preparation of monoacyl polyalkylene polyamines which results in good yields and low diamide contamination.
It is a still further object of the present invention to provide a process for the preparation of monoacyl polyalkylene polyamines which can be carried out at relatively low temperatures and is, therefore, energy efficient.
Other objects and advantages of the present invention will be set forth in or apparent from the following description.